#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
#include<assert.h>

size_t  my_strlen(char* arr)
{
    assert(arr != NULL);
    size_t con = 0;
    while (*arr++)
    {
        con++;
    }
    return con;
}
int main()
{
    char arr[20] = "\0";
    scanf("%s", arr);
    size_t len = my_strlen(arr);
    printf("%zd", len);
    return 0;
}